The convex variable step-size (CVSS) algorithm

This letter introduces the convex variable step-size (CVSS) algorithm. The convexity of the resulting cost function is guaranteed. Simulations presented show that with the proposed algorithm, we obtain similar results, as with the VSS algorithm in initial convergence, while there are potential performance gains when abrupt changes occur.

Mapping the Governance Reform of Welfare to Work in Britain under New Labour

This article draws on Newman's (2001, 2007) typology of the modernization of governance under New Labor, to examine the development of British welfare to work administration. Concentrating on the delivery of active labor market policy, the article suggests network forms of governance occupy a marginal role in welfare to work delivery. Managerialist and hierarchical forms of governance dominate administration of activation policy. In accordance with UK tradition, a national centralized, top down system exercises control of social security and employment services administration, but increasingly seeks to realize its goals through a market system of delivery.

Reducing the mapping between perception and action facilitates imitation

This study investigated two hypotheses regarding the mapping of perception to action during imitation. The first hypothesis predicted that as children’s cognitive capacities increase the tendency to map one goal and disregard others during imitation should decrease. This hypothesis was tested by comparing the performances of 168 4- to 7-year-olds in a gestural imitation task developed by Bekkering, Wohlschläger, and Gattis. The second hypothesis predicted that reducing the mapping between perception and action should reduce the demands on the cognitive resources of the child. This hypothesis was tested by creating a condition in which perception and action overlapped by sharing objects between experimenter and child. In three experimental conditions, an adult modelled four gestures, directed at either: 1) one of two sets of round stickers (proprietary objects); 2) the same location on the table, without any sticker (no objects); or 3) one set of round stickers, which were shared with the child (shared objects). The results confirmed both hypotheses. Four- and five-year-olds imitated less accurately when imitation involved mapping of both objects and movements (proprietary and shared objects) than when imitation involved mapping movements only (no objects). Seven-year-olds imitated accurately in all three conditions, demonstrating that increased cognitive capacity allowed them to map multiple goals from perception to action. Most importantly, reducing the mapping between perception and action in the shared objects condition facilitated imitation, specifically for the transitional group, 6-year-olds. We conclude that mapping between perception and action is not direct, but resembles mapping relations in analogical reasoning: cognitive processes mediate mapping from perception to action.

Application of connectivity mapping in predictive toxicology based on gene-expression similarity.

Connectivity mapping is the process of establishing connections between different biological states using gene-expression profiles or signatures. There are a number of applications but in toxicology the most pertinent is for understanding mechanisms of toxicity. In its essence the process involves comparing a query gene signature generated as a result of exposure of a biological system to a chemical to those in a database that have been previously derived. In the ideal situation the query gene-expression signature is characteristic of the event and will be matched to similar events in the database. Key criteria are therefore the means of choosing the signature to be matched and the means by which the match is made. In this article we explore these concepts with examples applicable to toxicology.

Three dimensional number density mapping in the plume of a low temperature laser ablated magnesium plasma

Simultaneous optical absorption and laser-induced fluorescence measurements have been used to map the three-dimensional number densities of ground-state ions and neutrals within a low-temperature KrF laser-produced magnesium plasma expanding into vacuum. Data is reported for the symmetry plane of the plasma, which includes the laser interaction point at a delay of 1 μs after the ∼30 ns KrF laser ablation pulse and for a laser fluence of 2 J cm−2 on target. The number density distributions of ion and neutral species within this plane indicate that two distinct regions exist within the plume; one is a fast component containing ions and neutrals at maximum densities of ∼3×1013 cm−3 and ∼4×1012 cm−3, respectively and the second is a high-density region containing slow neutral species, at densities up to ∼1×1015 cm−3.

Quantitative mapping of aqueous microfluidic temperature with sub-degree resolution using fluorescence lifetime imaging microscopy

The use of a water-soluble, thermo-responsive polymer as a highly sensitive fluorescence-lifetime probe of microfluidic temperature is demonstrated. The fluorescence lifetime of poly(N-isopropylacrylamide) labelled with a benzofurazan fluorophore is shown to have a steep dependence on temperature around the polymer phase transition and the photophysical origin of this response is established. The use of this unusual fluorescent probe in conjunction with fluorescence lifetime imaging microscopy (FLIM) enables the spatial variation of temperature in a microfluidic device to be mapped, on the micron scale, with a resolution of less than 0.1 degrees C. This represents an increase in temperature resolution of an order of magnitude over that achieved previously by FLIM of temperature-sensitive dyes